The Imaging and Biosensor Core will provide specialized imaging techniques and fluorescence biosensors for the three component projects. Laser scanning and spinning disc confocal microscopy, multi-photon microscopy, multi-line total internal reflection fluorescence (TIRF) microscopy, FRAP, photoactivation and CALI (Chromophore Assisted Laser Inactivation) will be provided for the investigators. In addition, the Core will be able to provide traction force imaging as needed. Training of individuals from the component projects and advice on the design of imaging experiments will be provided. The core will also provide live cell biosensors for Rho family proteins and SGEF, and assist in their application. The Hahn lab has pioneered study of Rho family protein activation in living cells. Program project members will use published biosensors together with recently developed approaches that greatly enhance sensitivity and decrease perturbation of living cells. The core will also assist in application of biosensors developed by other laboratories. The Core Director has a long history of producing seminal developments in imaging methodogies (FRAP, single particle tracking, traction force imaging, and photoactivation and CALI as applied to cell adhesion and migration). Similarly, the Core Co-director has been a leader in the field of biosensor development (live cell indicators of Calmodulin-calcium binding, Rac, Cdc42 and Rho nucleotide state, MAP kinase phosphorylation, and fluorescent dyes for imaging of protein activity in vivo).